Core Component B, the Signaling and Motility Assays Core, will provide the expertise, protocols, analysis and interpretation of in vitro assays that examine the individual behavior, and interaction of tumor and stromal cells. The Core performs assays examining two-dimensional motile cell behavior, three-dimensional invasion, angiogenesis and transendothelial migration. These assays permit a comprehensive examination of cell behavior during chemotaxis, and provide a rapid and complete analysis of the invasive capabilities of a given cell type prior to costly and time-consuming animal studies. Moreover these in vitro assays support and complement the in vivo studies provided by the Intravital Imaging, Invasive Cell Collection and Expression Profiling Core (Core A). Core B will also act as a liaison for the use of unique protein biosensors and for assays examining invadopod formation so that the application of these technologies is uniform amongst the projects. The in vitro assays supported by Core B provide much needed information about cellular behavior and mechanism during tumor cell invasion and intravasation.The leading cause of death in cancer patients is the ability of tumor cells to leave the primary tumor, travel to distant sites within the body and form secondary tumors. The assays provided by this Core specifically examine the individual behavior and interaction of tumor and stromal cells, and will provide the foundation for understanding the mechanisms regulating tumor cell motility and invasion.